Correlation of Total and Angler-Acceptable Crappie Standing Stocks with Lake Basin Slopes and Siltation Indexes

Abstract

Fifty-seven Iowa lakes were classified into five groups using mean basin slopes and adjusted siltation indexes. Crappie (Pomoxis spp.) standing stocks were estimated in 16 lakes by applying rotenone to two or three small coves in each lake. Estimated total standing stocks of crappie ranged from 16 lbs/acre to 306 lbs/acre. Mean standing stocks of crappie for five lake groups were 66, 160, 108, 104, and 56 lbs/acre for Group I, II, III, IV, and V lakes, respectively. Standing stocks of crappie of a size acceptable to anglers ranged from 0 to 115 lbs/acre for individual lakes. A diversity index revealed greater diversity of crappie standing stock in the best fishing lakes and lower diversity in the poorest fishing lakes. Recommendations for crappie management for each lake type were made.